High rates of mental illness, HIV/AIDS/STI, and incarceration among African Americans (AA) reflect significant health disparities (NIH 2001 strategic plan to eliminate health disparities), particularly among youth. Teens in juvenile justice are disproportionately AA, and compared to the general population, juvenile offenders (JO) report more risky sexual behavior, drug and alcohol use, and psychiatric disorders, and are more likely to test positive for STIs. Still, few empirically-supported, theoretically-driven programs exist to address their negative health outcomes. This proposal addresses these health disparities by testing an innovative and uniquely tailored HIV/AIDS/STI, mental health, and substance use program designed for and pilot tested with recently arrested 13 - 17 year-old urban males and females (85% African American, 14% Latino/a) released on probation (PHAT Life; R34MH075628). PHAT Life was derived from a carefully staged process that included an active, diverse, multi-disciplinary advisory board, a youth advisory board, focus groups, two pilot tests, extensive feedback, and a series of curriculum revisions over three years. The R34 established feasibility and acceptability, revealed positive youth and stakeholder feedback, and yielded good preliminary outcomes at 3-month follow-up (e.g., increased condom use) to justify an efficacy trial. This application proposes a 2-arm randomized controlled trial to test PHAT Life versus a health promotion program with recently arrested 13-17 year-old male and female, mostly ethnic minority JO (as representative of Cook County) on probation in Chicago. We will use the procedures and methods established in the developmental study to recruit, enroll, assess, track, and intervene with teens. We will randomly assign youth to PHAT Life (N=150) or a health promotion control group (N=150), and we will deliver the interventions in single sex groups of 5 - 7 teens at Evening Reporting Centers. Assessments will occur at baseline, 6-, and 12-months post-treatment, and we will screen youth for three common STIs (Chlamydia, Gonorrhea, Trichamonas) at baseline and 12-month follow-up. All youth who test positive for an STI will receive single dose antibiotic treatment free of charge. Using an intent-to-treat analysis, we will test and compare PHAT Life to the health promotion control group on adolescent risky sexual behavior, substance use, and theoretical mediators. This proposal answers a compelling need for innovative prevention programs that address the intersecting health disparities of mental illness and HIV/AIDS/STIs among youth in juvenile justice. Without intervention, these teens continue to engage in risk behaviors post-release, amplifying their own and their partner's risk for HIV/AIDS/STIs.26, 27 The lasting effects on community well-being, individual employment prospects, and neighborhood health28 are profound, but effective programs can alter the negative developmental trajectories of this very high-risk population29, 30 and begin to redress existing health disparities.